The USGBC currently leads the United States market in green building ratings systems, offering LEED rating systems for new construction, existing buildings, core-and-shell, and commercial interiors, as well as neighborhood development. LEED rating systems continue to grow and evolve, gaining in complexity as the sustainability movement changes.
Per the USGBC, LEED for New Construction & Major Renovations (LEED-NC) takes an integrative approach to producing buildings that are designed to be efficient and have a lower impact on their environment.
LEED 2009 for New Construction is still in place under a sunset provision that allows both LEED 2009 and LEED v4 to coexist. At this time, both rating systems are applicable through June 1, 2015, after which the system will advance fully to LEED v4. Its predecessors include LEED v 1.0, 2.0, 2.1, and 2.2. A small number of parking structures were certified under LEED NC v 2.2, prior to the release of LEED 2009 and evolving Minimum Program Requirements.
Under v 2.2 and LEED 2009, the USGBC applies five main credit categories that contain multiple sustainable strategies under each heading. These include Sustainable Sites (SS), Water Efficiency (WE), Energy and Atmosphere (EA), Materials and Resources (MR), and Indoor Environmental Quality (IEQ). An additional category exists, termed Innovation and Design (ID). ID credits include exemplary performance as well as innovations not covered by the existing rating system.
The systems include both prerequisites and credits in each area. All prerequisites must be met for a building to achieve any level of certification. A building’s owner seeks to achieve a certain number of credits throughout the design and construction process, and points are allocated based on the relative importance of building-related impacts.
Prerequisites for LEED 2009 include the following, which may all be achieved by parking structures designed with the rating system in mind. Within each of these prerequisites, parking structures may present unique challenges and applications. In addition, all buildings must integrate at least 1,000 square feet of conditioned space and provide space for a minimum of one full time equivalent (FTE) occupant.
Parking garages have been specifically addressed in the Minimum Program Requirements (MPR) for LEED and the associated Supplementary Guidance to the MPR.
These documents clarify the USGBC position on parking structures and their eligibility for certification, reflecting an evolving perspective on how the USGBC addresses parking structures and parking as a component of mixed-use buildings:
This interpretation may evolve as new projects pursue certification and create a body of experience and inquires that require further clarification. Parking structures may add credits to a project if they lie within the LEED project boundary. In this fashion, a stand-alone garage with no mixed-use space that is adjacent to an office building may contribute credits to the project.
In many cases, garages will provide credits to adjacent buildings (here, both buildings are considered a single project according to the LEED boundary and certification process). In this scenario, a garage may offer significant credit value under the Sustainable Sites category, especially with regard to the alternative transportation credits.
(Please note: These approaches will evolve further under LEED v4 and systems that evolve from it. For the most up-to-date information, please refer to usgbc.org.)